The 2-cohomology of the group $\Omega^-(4,q)$ with coefficients in the natural module

The 2-cohomology group is determined for the finite simple orthogonal group $\Omega^-(4,q)$, where $q$ is odd, with coefficients in the natural module. For $q\ne9$ this group is trivial, and for $q=9$ it is isomorphic to $Z_3^4$. Thus Küsefoglu's result is corrected.
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